Random-Access Procedure

ABSTRACT

A method in a network node for managing random-access procedures with a plurality of wireless devices. The method comprising transmitting an indication of a modulation format to one or more of the plurality of wireless devices to configure the modulation format for a random access message (3) transmission from the one or more wireless devices.

TECHNICAL FIELD

The present disclosure relates, in general, to wireless communicationsand, more particularly, to a random-access response procedure.

BACKGROUND

A random-access procedure is a key function in a cellular system. FIG. 1illustrates the random-access procedure in LTE. A similar structure isexpected to be used in 5G New Radio (NR). In 4G LTE, a UE that wouldlike to access the network initiates the random-access procedure bytransmitting a preamble (Msg1), 30, in the uplink on the PhysicalRandom-Access Channel (PRACH). A base station receiving the preamble anddetecting the random-access attempt will respond in the downlink bytransmitting a random-access response (Msg2), 40, on the PhysicalDownlink Shared Channel (PDSCH). The random-access response carries anuplink scheduling grant for the UE to continue the procedure bytransmitting a subsequent message in the uplink (Msg3), 50, on thePhysical Uplink Shared Channel (PUSCH) for terminal identification.

The 4G wireless access within LTE is based on OFDM in downlink andDFT-spread OFDM (DFTS-OFDM, a.k.a. SC-FDMA) in uplink [see 3GPP TS36.211]. An illustration of DFT-spread OFDM is shown in FIG. 2, wherethe information bits are used to calculate an error detection code (CRC,Cyclic Redundancy Check), channel coded, rate matched and modulated tocomplex valued symbols such as QPSK, 16QAM or 64QAM. Symbolscorresponding to several control entities and symbols corresponding topayload are then multiplexed, pre-coded by a DFT (transform precoding),mapped to a frequency interval in which it is allocated, transformed tothe time domain, concatenated with a cyclic prefix and finallytransmitted over air. The order of some of the processing blocks mightbe changed. For example, the modulation might be placed after themultiplexing instead of before.

The symbol constructed by the DFT, mapping, IFFT and CP insertion isdenoted as a SC-FDMA symbol in [3GPP TS 36.211, section 5.6]. Within LTErelease 8, a TTI is constructed by 14 such SC-FDMA symbols.

This DFT-spread OFDM as used in uplink has significantly lower Peak toAverage Power Ratio (PAPR) as compared to OFDM. By having a low PAPR,the transmitter can be equipped with simpler and less energy consumingradio equipment, which is important for user devices where cost andbattery consumptions are important issues. Also, the UE can use highertransmit power for DFTS-OFDM as compared to OFDM. In future 5G systems,this single carrier property with low PAPR might be important not onlyfor power limited UEs in uplink but also for downlink and device todevice transmissions.

In LTE, the message 3 is based on DFTS-OFDM. An illustration is given inFIG. 3 of one sub-frame with 14 DFTS-OFDM symbols, where two DFTS-OFDMsymbols are used for demodulation reference signals.

An illustration of ordinary OFDM is given in FIG. 4. Here, the DFTbefore the mapping is removed, as compared to DFTS-OFDM in FIG. 2. Anillustration is given in FIG. 5 of several sub-frames, each with 14 OFDMsymbols, including reference signals.

Within 5G NR, the air interfaces between uplink and downlink should bealigned. One suggestion may be to use OFDM in both downlink and uplink.Another reason for using OFDM in the uplink is multi-layer transmission(MIMO) where multiple layers are spatially multiplexed from a single UE.With OFDM, the base station receiver may become simpler. The use of OFDMalso allows for more flexibility in terms of multiplexing differentsignals as not only the time domain can be used but also the frequencydomain. Hence, for NR it has been agreed to support both OFDM andDFTS-OFDM.

With message 3 modulation format based on OFDM, some UEs will experiencecoverage issues when using lower transmit power with OFDM as compared tousing DFTS-OFDM. Also, an OFDM transmission might have to use lowertransmit power as compared to the PRACH preamble, if the PRACH preambleis constructed to have low PAPR. This is because a larger backoff mustbe used in the power amplifier for an OFDM transmission as compared totransmitting with DFTS-OFDM.

If message 3 modulation format is always based on DFTS-OFDM, then allbase stations need both an OFDM and an DFTS-OFDM receiver. Furthermore,a somewhat higher resource overhead might be needed for DFTS-OFDM ascompared to OFDM.

SUMMARY

In an embodiment a method in a network node for managing random-accessprocedures with a plurality of wireless devices is disclosed. The methodcomprises transmitting an indication of a modulation format to one ormore of the plurality of wireless devices to configure the modulationformat for a random access message 3 transmission from the one or morewireless devices. This provides the advantage that the modulation formatcan be selected depending on certain network conditions and therefore amore optimum modulation format may be applied.

In one example the indicated modulation format is either DiscreteFourier Transform Spread-Orthogonal Frequency Division Multiplexing,DFTS-OFDM, or OFDM.

In another example the the random access message 3 is the third messagein a random access sequence, wherein a first random access messagecomprises a random access preamble and a second random access messagecomprises a random access response, RAR.

In some examples the indicated modulation format applies to future datatransmissions from the wireless device.

In one aspect transmitting the indication of a modulation formatcomprises an indication within a broadcast channel. In some examplestransmitting the indication of a modulation format comprises anindication within System Information.

In another aspect transmitting the indication of a modulation formatcomprises an indication within a Random Access Response, RAR, message.

In some examples the indication is an implicit indication of amodulation format.In another aspect the method further comprises selecting the modulationformat, wherein the selection is based on one or more of: a capabilityof the network node, a link budget for the wireless device, an overheadof transmissions to be transmitted by the wireless device, a determinedpower level and/or signal to noise ratio, SNR, of the wireless deviceand a random access preamble detection criterion.

In another aspect the method further comprises receiving a transmissionfrom the wireless device according to the indicated modulation format.In some examples the received transmission is in response to an uplinkscheduling grant included in the random access response message.

In another aspect the indication of a modulation format furthercomprises an indication of a plurality of modulation formats andreceiving an indication from the wireless device of a selected one ofthe plurality of modulation formats. In some examples the plurality ofmodulation formats comprises Discrete Fourier TransformSpread-Orthogonal Frequency Division Multiplexing, DFTS-OFDM, and OFDM.

In another embodiment a method in a wireless device for performing arandom-access procedure with a network node is provided. The methodcomprises receiving, from a network node, an indication of a modulationformat for a random access message 3 transmission to the network node.The method further comprises transmitting the random access message 3according to the indicated modulation format.

In one aspect the indication of a modulation format comprises anindication of a plurality of modulation formats and the method furthercomprises selecting one of the plurality of modulation formats; andtransmitting an indication of the selected modulation format to thenetwork node.

In another embodiment a network node operable to manage a random-accessprocedure with a wireless device is provided The network node isconfigured to transmit an indication of a modulation format to thewireless device to configure the modulation format to be used for arandom access message 3 transmission from the wireless device.

In one aspect the network node is further configured to select themodulation format, wherein the selection is based on one or more of: acapability of the network node, a link budget for the wireless device,an overhead of transmissions to be transmitted by the wireless device, adetermined power level and/or signal to noise ratio, SNR, of thewireless device and a random access preamble detection criterion.

In another aspect the indication of a modulation format comprises anindication of a plurality of modulation formats, and the network node isfurther configured to receive an indication from the wireless device ofa selected one of the plurality of modulation formats.

In one example the network node is further configured to receive atransmission from the wireless device according to the selectedmodulation format.

In some examples the received transmission is in response to an uplinkscheduling grant included in the random access response message.

In further embodiment a wireless device operable to perform arandom-access procedure with a network node is disclosed. The wirelessdevice is configured to receive an indication of a modulation format fora random access message 3 transmission to the network node and transmitthe random access message 3 according to the indicated modulationformat.

In some examples the modulation format is either Discrete FourierTransform Spread-Orthogonal Frequency Division Multiplexing, DFTS-OFDM,or OFDM. In some examples the random access message 3 is the thirdmessage in a random access sequence, wherein a first random accessmessage comprises a random access preamble and a second random accessmessage comprises a random access response, RAR. In some examples theindication of the modulation format applies to future data transmissionsfrom the wireless device.

In one aspect the indication of the modulation format comprises anindication within a broadcast channel. In some examples the indicationof the modulation format comprises an indication within SystemInformation, SI.

In another aspect the indication of the modulation format comprises anindication within a Random Access Response, RAR, message.

In some examples the indication is an implicit indication of amodulation format.

In another aspect the indication of a modulation format comprises anindication of a plurality of modulation formats and the wireless deviceis further configured to select a modulation format and transmit anindication of the selected modulation format to the network node. Insome examples the plurality of modulation formats comprises DiscreteFourier Transform Spread-Orthogonal Frequency Division Multiplexing,DFTS-OFDM, and OFDM.

In another embodiment a network node comprising a transceiver, aprocessor and a memory is disclosed, wherein the network node isoperable to manage a random-access procedure with a wireless device,wherein the processor is configured to transmit, via the transceiver, anindication of a modulation format to the wireless device to configurethe modulation format to be used for a random access message 3transmission from the wireless device.

In another embodiment a wireless device comprising a transceiver, aprocessor and a memory is disclosed, wherein the wireless device isoperable to perform a random-access procedure with a network node,wherein the processor is configured to receive, via the transceiver anindication of a modulation format for a random access message 3transmission to the network node; and transmit, via the transceiver, arandom access message 3 according to the indicated modulation format.

In a further embodiment a computer program, computer program product orcarrier, containing instructions is disclosed, wherein the instructionswhen executed on a computer perform any one of the methods in claims 1to 22.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a scenario in which embodiments of the presentdisclosure may be applied.

FIG. 2 illustrates an example procedure in which embodiments of thepresent disclosure may be applied.

FIG. 3 illustrates an example scenario in which embodiments of thepresent disclosure may be applied.

FIG. 4 illustrates further example procedure in which embodiments of thepresent disclosure may be applied.

FIG. 5 illustrates a further example scenario in which embodiments ofthe present disclosure may be applied.

FIG. 6 illustrates an example environment of embodiments of the presentdisclosure.

FIG. 7 illustrates an example scenario of an embodiment of the presentdisclosure.

FIG. 8 is a block diagram illustrating example physical units of anetwork node according to one or more embodiments of the presentdisclosure.

FIG. 9 is a block diagram illustrating example physical units of awireless device according to one or more embodiments of the presentdisclosure.

FIG. 10 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments.

FIG. 11 is a block schematic of an exemplary network node, in accordancewith certain embodiments

FIG. 12 is a block schematic of an exemplary radio network controller orcore network node 130, in accordance with certain embodiments.

FIG. 13 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments.

FIG. 14 is a block schematic of an exemplary network node, in accordancewith certain embodiments

FIG. 15 shows an example method in a base station in accordance withcertain embodiments.

FIG. 16 shows an example method in a wireless device or UE in accordancewith certain embodiments.

DETAILED DESCRIPTION

In some embodiments, a message is introduced in the random-accessresponse (RAR) or with a broadcast channel which configures the UE totransmit message 3 with OFDM or DFTS-OFDM. As an advantage, theselection between the modulation formats for message 3 can be based onthe capabilities of receivers in the base station, the link budget foran individual UE, and/or the affordable overhead of the message 3.

FIG. 6 is a block diagram illustrating an embodiment of a network 100,in accordance with certain embodiments. Network 100 includes one or moreUser Equipment, UE(s), 110 (which may be interchangeably referred to aswireless devices 110) and one or more network node(s) 115 (which may beinterchangeably referred to as eNBs or gNBs 115). UEs 110 maycommunicate with network nodes 115 over a wireless interface. Forexample, a UE 110 may transmit wireless signals to one or more ofnetwork nodes 115, and/or receive wireless signals from one or more ofnetwork nodes 115. The wireless signals may contain voice traffic, datatraffic, control signals, and/or any other suitable information. In someembodiments, an area of wireless signal coverage associated with anetwork node 115 may be referred to as a cell 125. In some embodiments,UEs 110 may have device-to-device (D2D) capability. Thus, UEs 110 may beable to receive signals from and/or transmit signals directly to anotherUE. In certain embodiments, network nodes 115 may transmit one or morebeams, and one or more UE 110 may be asked to monitor these beams fromone or more of network nodes 115.

In certain embodiments, network nodes 115 may interface with a radionetwork controller. The radio network controller may control networknodes 115 and may provide certain radio resource management functions,mobility management functions, and/or other suitable functions. Incertain embodiments, the functions of the radio network controller maybe included in network node 115. The radio network controller mayinterface with a core network node. In certain embodiments, the radionetwork controller may interface with the core network node via aninterconnecting network 120. Interconnecting network 120 may refer toany interconnecting system capable of transmitting audio, video,signals, data, messages, or any combination of the preceding.Interconnecting network 120 may include all or a portion of a publicswitched telephone network (PSTN), a public or private data network, alocal area network (LAN), a metropolitan area network (MAN), a wide areanetwork (WAN), a local, regional, or global communication or computernetwork such as the Internet, a wireline or wireless network, anenterprise intranet, or any other suitable communication link, includingcombinations thereof.

In some embodiments, the core network node may manage the establishmentof communication sessions and various other functionalities for UEs 110.UEs 110 may exchange certain signals with the core network node usingthe non-access stratum layer. In non-access stratum signaling, signalsbetween UEs 110 and the core network node may be transparently passedthrough the radio access network. In certain embodiments, network nodes115 may interface with one or more network nodes over an internodeinterface, such as, for example, an X2 interface.

As described above, example embodiments of network 100 may include oneor more wireless devices 110, and one or more different types of networknodes capable of communicating (directly or indirectly) with wirelessdevices 110.

In some embodiments, the non-limiting term UE is used. UEs 110 describedherein can be any type of wireless device capable of communicating withnetwork nodes 115 or another UE over radio signals. UE 110 may also be aradio communication device, target device, D2D UE,machine-type-communication UE or UE capable of machine to machinecommunication (M2M), low-cost and/or low-complexity UE, a sensorequipped with UE, Tablet, mobile terminals, smart phone, laptop embeddedequipped (LEE), laptop mounted equipment (LME), USB dongles, CustomerPremises Equipment (CPE), etc. UE 110 may operate under either normalcoverage or enhanced coverage with respect to its serving cell. Theenhanced coverage may be interchangeably referred to as extendedcoverage. UE 110 may also operate in a plurality of coverage levels(e.g., normal coverage, enhanced coverage level 1, enhanced coveragelevel 2, enhanced coverage level 3 and so on). In some cases, UE 110 mayalso operate in out-of-coverage scenarios.

Also, in some embodiments generic terminology, “radio network node” (orsimply “network node”) is used. It can be any kind of network node,which may comprise a base station (BS), radio base station (RBS), NodeB, multi-standard radio (MSR) radio node such as MSR BS, evolved Node B(eNB), gNB network controller, radio network controller (RNC), basestation controller (BSC), relay node, relay donor node controllingrelay, base transceiver station (BTS), access point (AP), radio accesspoint, transmission points, transmission nodes, Remote Radio Unit (RRU),Remote Radio Head (RRH), nodes in distributed antenna system (DAS),Multi-cell/multicast Coordination Entity (MCE), core network node (e.g.,MSC, MME, etc.), O&M, OSS, SON, positioning node (e.g., E-SMLC), MDT, orany other suitable network node.

The terminology such as network node and wireless device or UE should beconsidered non-limiting and does in particular not imply a certainhierarchical relation between the two; in general “eNodeB” could beconsidered as device 1 and “UE” device 2, and these two devicescommunicate with each other over some radio channel.

Example embodiments of UE 110, network nodes 115, and other networknodes (such as radio network controller or core network node) aredescribed in more detail below with respect to FIGS. 8-14.

Although FIG. 6 illustrates a particular arrangement of network 100, thepresent disclosure contemplates that the various embodiments describedherein may be applied to a variety of networks having any suitableconfiguration. For example, network 100 may include any suitable numberof UEs 110 and network nodes 115, as well as any additional elementssuitable to support communication between UEs or between a UE andanother communication device (such as a landline telephone).Furthermore, although certain embodiments may be described asimplemented in 5G network, the embodiments may be implemented in anyappropriate type of telecommunication system supporting any suitablecommunication standards and using any suitable components, and areapplicable to any radio access technology (RAT) or multi-RAT systems inwhich a UE receives and/or transmits signals (e.g., data). For example,the various embodiments described herein may be applicable to LTE,LTE-Advanced, 5G, NR, UMTS, HSPA, GSM, cdma2000, WCDMA, WiMax, UMB,WiFi, another suitable radio access technology, or any suitablecombination of one or more radio access technologies. Although certainembodiments may be described in the context of wireless transmissions inthe downlink, the present disclosure contemplates that the variousembodiments are equally applicable in the uplink.

In some embodiments, an additional bit field is included in RAR if theRAR indicates the use of OFDM versus DFTS-OFDM. This field may be calledthe “modulation format.” This RAR can be UE specific, PRACH preamblespecific or common for a group of UEs. In the latter case, several UEscan be specified with one single modulation format field. The modulationformat could also be implicitly signaled, e.g. tied to a certainresource allocation in the uplink grant, tied to the DL resources usedto transmit the RAR, derived from the TC-RNTI, or depend on the back-offindicator.

In some embodiments, the “modulation format” may be indicated in abroadcast channel and transmitted in a non UE-specific manner. A variantof this may be to tie the uplink waveform to some quantity used duringthe downlink cell search and synchronization such as the synchronizationsequence (one set of sync sequences or cell IDs means DFTS-OFDM, anotherset means OFDM). The broadcast channel could be the master informationblock (MIB) or a system information block (SIB) which is read by the UEprior to performing a random-access. In other words, the broadcastchannel may include a master information block (MIB) or a systeminformation block (SIB).

In some embodiments, the selection of modulation format can be basedupon PRACH preamble detection. If the PRACH preamble is detected withlow power or with a low SNR, then this may indicate that the UE is powerlimited and the use of DFTS-OFDM is better than OFDM when transmittingmessage 3.

As stated above, some embodiments introduce a message in therandom-access response (RAR) and other embodiments use a broadcastchannel which configures the UE to transmit message 3 with OFDM orDFTS-OFDM.

The Random Access Response typically has the following payload:

-   -   Detected PRACH preamble index such as to acknowledge of PRACH        preamble    -   Timing Advance (TA) command to UE    -   Uplink scheduling grant to UE    -   Temporary identity (e.g. TC-RNTI)    -   Configuration of additional synchronization signals if needed    -   Back off Indicator (BI)

FIG. 7 illustrates a PRACH preamble detection criteria. This criterioncorresponds to received signal strength for a PRACH preamble. A preambledetection threshold is also included which is used such that a preambleis considered as detected if the PRACH preamble criteria exceeds thisthreshold. A second threshold is also included, for which the basestations order the UE to use OFDM for message 3 if the PRACH preamblecriteria is above this threshold and DFTS-OFDM otherwise. In theseembodiments, the modulation format field could be included in the RARtied to the detected PRACH preamble.

In some embodiments, the “modulation format” may be used to configuremore aspects of the message 3 transmissions such as number of OFDM (orDFTS-OFDM) symbols, reference signal density in time and frequency,number of layers, etc. This to adjust the message 3 format depending onlink budget, measured e.g. from received PRACH preamble. In this way,the resource allocation needed for message 3 can be lower when a UE hasa good link budget.

In some embodiments, the selection between DFTS-OFDM or OFDM in the RARis used to determine the uplink waveform also for future datatransmission, i.e. to make the RAR waveform selection “persistent.” Thismay avoid to have to inform the UE during subsequent data transmissionwhether to use DFTS-OFDM or OFDM.

If the message 3 modulation format is indicated in system information(SI) it could either specify just DFTS-OFDM or OFDM in which case the UEwould have to obey the configuration. System information (SI) maycomprise a master information block (MIB) or a system information block(SIB). However, the gNB could also indicate both OFDM and DFTS-OFDM. Inthis case one possibility would be the UE selects—based on e.g. itspower budget —one preamble transmission scheme and the gNB blindlydetects the transmission scheme. The blind decoding could be based onthe reference signal of message 3.

Another possibility is that gNB specifies two sets of PRACH preambles:UE selects preamble from first set if it wishes to use OFDM for message3 and selects preamble from second set if it wishes to use DFTS-OFDM formessage 3 (if a gNB specifies both preamble sets this is one possibilityto signal a gNB supports both OFDM and DFTS-OFDM for message 3 while ifonly one set has non-zero cardinality only the correspondingtransmission scheme is supported).

Based on, for example power of received PSS, SSS and PBCH, the UEselects a PRACH preamble of the first or second preamble set and by thatindicates OFDM or DFTS-OFDM for message 3. This received power can beused to calculate the path loss between gNB and UE. In another examplethe UE selects between OFDM and DFTS-OFDM based on PRACH preamble power.This PRACH preamble power can be based on calculated path loss or PRACHpower ramping. For example, in first transmission(s) UE selects preambleindicating OFDM, but if it must ramp its transmission power it switchesto a preamble indicating DFTS-OFDM.

A gNB receiving a PRACH preamble and granting a matching message 3transmission knows then which transmission scheme to expect for themessage 3 transmission. Optionally this scheme could still becomplemented with a modulation format bit in RAR to potentiallyoverwrite a UE preference for message 3 transmission scheme.

The selection of PRACH preamble group (which can be seen as implicitmodulation format bit conveyed from UE to gNB) can—as above—alsoconfigure more aspects of message 3.

As provided, in some embodiments the gNB specifies two different PRACHpreamble groups, one corresponding to OFDM, the other to DFTS-OFDMmessage 3 transmission. Instead of the PRACH preamble, some embodimentsmay use different PRACH formats or resources in time/frequencycorresponding to OFDM and DFTS-OFDM message 3 transmission.

FIG. 8 is a block schematic of an exemplary base station 800, inaccordance with certain embodiments. The example base station of FIG. 8may be configured to perform the functionality described above withrespect to FIGS. 1-7, or any example of the disclosure. The example basestation of FIG. 8 may be arranged with radio circuitry 810 tocommunicate with served UEs, communication circuitry 820 to communicatewith other radio network and core network and OAM system nodes, memory830 to store information related to the invention, and a processing unit840. The processing unit 840 may be configured to formulate the RARmessage to be provided to the UE. The memory 830 may be configured tostore information about served UEs and modulation formats. The radiocircuitry 810 may be configured to communicate with served UEs,including communicating a RAR message to the UE to transmit message 3with OFDM or DFTS-OFDM. In another example the radio circuitry 820 isconfigured to transmit the “modulation format” in a broadcast channeland transmitted in a non UE-specific manner. A variant of this may be totie the uplink waveform to some quantity used during the downlink cellsearch and synchronization such as the synchronization sequence (one setof sync sequences or cell IDs means DFTS-OFDM, another set means OFDM).In some examples the broadcast channel includes the master informationblock (MIB) or a system information block (SIB) which is read by the UEprior to performing a random-access.

FIG. 9 is a block schematic of an exemplary wireless device 900, inaccordance with certain embodiments. The example wireless device of FIG.9 may be configured to perform the functionality of UEs described abovewith respect to FIGS. 1-7, or any example of the disclosure. The examplewireless device 900 of FIG. 9 may be arranged with radio circuitry 910to communicate with the serving base station, memory 920 to storeinformation related to the invention, and a processing unit 930. Theradio circuitry 910 may be configured to communicate with the servingbase station, including receiving from the base station a RAR message totransmit message 3 with OFDM or DFTS-OFDM and responding with message 3in accordance with the message. In another example the radio circuitryis configured to receive the “modulation format” indicated in abroadcast channel and transmitted in a non UE-specific manner. A variantof this may be to tie the uplink waveform to some quantity used duringthe downlink cell search and synchronization such as the synchronizationsequence (one set of sync sequences or cell IDs means DFTS-OFDM, anotherset means OFDM). In some aspects the broadcast channel includes themaster information block (MIB) or a system information block (SIB) whichis read by the UE prior to performing a random-access. In other examplesthe gNB could also indicate both OFDM and DFTS-OFDM. In this case one inone example the processing unit is configured to select—based on e.g.the UE power budget—one preamble transmission, in other words select oneof the modulation formats.

The processing unit may be configured to formulate the message 3according to the indicated/selected modulation format. The memory may beconfigured to store information about the UE and other networkcomponents.

FIG. 10 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments. Wireless device 110 may refer toany type of wireless device communicating with a node and/or withanother wireless device in a cellular or mobile communication system.Examples of wireless device 110 include a mobile phone, a smart phone, aPDA (Personal Digital Assistant), a portable computer (e.g., laptop,tablet), a sensor, a modem, a machine-type-communication (MTC)device/machine-to-machine (M2M) device, laptop embedded equipment (LEE),laptop mounted equipment (LME), USB dongles, a D2D capable device, oranother device that can provide wireless communication. A wirelessdevice 110 may also be referred to as UE, a station (STA), a device, ora terminal in some embodiments. Wireless device 110 includes transceiver1310, processor 1320, and memory 1330. In some embodiments, transceiver1310 facilitates transmitting wireless signals to and receiving wirelesssignals from network node 115 (e.g., via antenna 1340), processor 1320executes instructions to provide some or all of the functionalitydescribed above as being provided by wireless device 110, and memory1330 stores the instructions executed by processor 1320.

Processor 1320 may include any suitable combination of hardware andsoftware implemented in one or more modules to execute instructions andmanipulate data to perform some or all of the described functions ofwireless device 110, such as the functions of wireless device 110described above in relation to FIGS. 1-9. For example, to communicatewith the serving base station, including receiving from the base stationa RAR message to transmit message 3 with OFDM or DFTS-OFDM andresponding with message 3 in accordance with the message. In anotherexample, to receive the “modulation format” indicated in a broadcastchannel and transmitted in a non UE-specific manner. A variant of thismay be to tie the uplink waveform to some quantity used during thedownlink cell search and synchronization such as the synchronizationsequence (one set of sync sequences or cell IDs means DFTS-OFDM, anotherset means OFDM). In some aspects the broadcast channel includes themaster information block (MIB) or a system information block (SIB) whichis read by the UE prior to performing a random-access. In other examplesthe gNB could also indicate both OFDM and DFTS-OFDM. In this case in oneexample the processor selects—based on e.g. the UE power budget—onepreamble transmission, in other words selects one of the modulationformats.

In some embodiments, processor 1320 may include, for example, one ormore computers, one or more central processing units (CPUs), one or moremicroprocessors, one or more applications, one or more applicationspecific integrated circuits (ASICs), one or more field programmablegate arrays (FPGAs) and/or other logic.

Memory 1330 is generally operable to store instructions, such as acomputer program, software, an application including one or more oflogic, rules, algorithms, code, tables, etc. and/or other instructionscapable of being executed by a processor. Examples of memory 1330include computer memory (for example, Random Access Memory (RAM) or ReadOnly Memory (ROM)), mass storage media (for example, a hard disk),removable storage media (for example, a Compact Disk (CD) or a DigitalVideo Disk (DVD)), and/or or any other volatile or non-volatile,non-transitory computer-readable and/or computer-executable memorydevices that store information, data, and/or instructions that may beused by processor 1020.

Other embodiments of wireless device 110 may include additionalcomponents beyond those shown in FIG. 10 that may be responsible forproviding certain aspects of the wireless device's functionality,including any of the functionality described above and/or any additionalfunctionality (including any functionality necessary to support thesolution described above). As just one example, wireless device 110 mayinclude input devices and circuits, output devices, and one or moresynchronization units or circuits, which may be part of the processor1320. Input devices include mechanisms for entry of data into wirelessdevice 110. For example, input devices may include input mechanisms,such as a microphone, input elements, a display, etc. Output devices mayinclude mechanisms for outputting data in audio, video and/or hard copyformat. For example, output devices may include a speaker, a display,etc.

FIG. 11 is a block schematic of an exemplary network node, in accordancewith certain embodiments. Network node 115 may be any type of radionetwork node or any network node that communicates with a UE and/or withanother network node. Examples of network node 115 include an eNodeB, agNB, a node B, a base station, a wireless access point (e.g., a Wi-Fiaccess point), a low power node, a base transceiver station (BTS),relay, donor node controlling relay, transmission points, transmissionnodes, remote RF unit (RRU), remote radio head (RRH), multi-standardradio (MSR) radio node such as MSR BS, nodes in distributed antennasystem (DAS), O&M, OSS, SON, positioning node (e.g., E-SMLC), MDT, orany other suitable network node. Network nodes 115 may be deployedthroughout network 100 as a homogenous deployment, heterogeneousdeployment, or mixed deployment. A homogeneous deployment may generallydescribe a deployment made up of the same (or similar) type of networknodes 115 and/or similar coverage and cell sizes and inter-sitedistances. A heterogeneous deployment may generally describe deploymentsusing a variety of types of network nodes 115 having different cellsizes, transmit powers, capacities, and inter-site distances. Forexample, a heterogeneous deployment may include a plurality of low-powernodes placed throughout a macro-cell layout. Mixed deployments mayinclude a mix of homogenous portions and heterogeneous portions.

Network node 115 may include one or more of transceiver 1410, processor1420, memory 1430, and network interface 1440. In some embodiments,transceiver 1410 facilitates transmitting wireless signals to andreceiving wireless signals from wireless device 110 (e.g., via antenna1450), processor 1420 executes instructions to provide some or all ofthe functionality described above as being provided by a network node115, memory 1430 stores the instructions executed by processor 1420, andnetwork interface 1440 communicates signals to backend networkcomponents, such as a gateway, switch, router, Internet, Public SwitchedTelephone Network (PSTN), core network nodes or radio networkcontrollers 130, etc.

Processor 1420 may include any suitable combination of hardware andsoftware implemented in one or more modules to execute instructions andmanipulate data to perform some or all of the described functions ofnetwork node 115, such as those described above in relation to FIGS. 1-9above. For example to communicate with served UEs, includingcommunicating a RAR message to the UE to transmit message 3 with OFDM orDFTS-OFDM. In another example to transmit the “modulation format” in abroadcast channel and transmitted in a non UE-specific manner. A variantof this may be to tie the uplink waveform to some quantity used duringthe downlink cell search and synchronization such as the synchronizationsequence (one set of sync sequences or cell IDs means DFTS-OFDM, anotherset means OFDM). In some aspects the broadcast channel includes themaster information block (MIB) or a system information block (SIB) whichis read by the UE prior to performing a random-access.

In some embodiments, processor 1420 may include, for example, one ormore computers, one or more central processing units (CPUs), one or moremicroprocessors, one or more applications, and/or other logic.

Memory 1430 is generally operable to store instructions, such as acomputer program, software, an application including one or more oflogic, rules, algorithms, code, tables, etc. and/or other instructionscapable of being executed by a processor. Examples of memory 1430include computer memory (for example, Random Access Memory (RAM) or ReadOnly Memory (ROM)), mass storage media (for example, a hard disk),removable storage media (for example, a Compact Disk (CD) or a DigitalVideo Disk (DVD)), and/or or any other volatile or non-volatile,non-transitory computer-readable and/or computer-executable memorydevices that store information.

In some embodiments, network interface 1440 is communicatively coupledto processor 1420 and may refer to any suitable device operable toreceive input for network node 115, send output from network node 115,perform suitable processing of the input or output or both, communicateto other devices, or any combination of the preceding. Network interface1440 may include appropriate hardware (e.g., port, modem, networkinterface card, etc.) and software, including protocol conversion anddata processing capabilities, to communicate through a network.

Other embodiments of network node 115 may include additional componentsbeyond those shown in FIG. 11 that may be responsible for providingcertain aspects of the radio network node's functionality, including anyof the functionality described above and/or any additional functionality(including any functionality necessary to support the solutionsdescribed above). The various different types of network nodes mayinclude components having the same physical hardware but configured(e.g., via programming) to support different radio access technologies,or may represent partly or entirely different physical components.

FIG. 12 is a block schematic of an exemplary radio network controller orcore network node 130, in accordance with certain embodiments. Examplesof network nodes can include a mobile switching center (MSC), a servingGPRS support node (SGSN), a mobility management entity (MME), a radionetwork controller (RNC), a base station controller (BSC), and so on.The radio network controller or core network node 130 includes processor1520, memory 1530, and network interface 1540. In some embodiments,processor 1520 executes instructions to provide some or all of thefunctionality described above as being provided by the network node,memory 1530 stores the instructions executed by processor 1520, andnetwork interface 1540 communicates signals to any suitable node, suchas a gateway, switch, router, Internet, Public Switched TelephoneNetwork (PSTN), network nodes 115, radio network controllers or corenetwork nodes 130, etc.

Processor 1520 may include any suitable combination of hardware andsoftware implemented in one or more modules to execute instructions andmanipulate data to perform some or all of the described functions of theradio network controller or core network node 130. In some embodiments,processor 1520 may include, for example, one or more computers, one ormore central processing units (CPUs), one or more microprocessors, oneor more applications, and/or other logic.

Memory 1530 is generally operable to store instructions, such as acomputer program, software, an application including one or more oflogic, rules, algorithms, code, tables, etc. and/or other instructionscapable of being executed by a processor. Examples of memory 1530include computer memory (for example, Random Access Memory (RAM) or ReadOnly Memory (ROM)), mass storage media (for example, a hard disk),removable storage media (for example, a Compact Disk (CD) or a DigitalVideo Disk (DVD)), and/or or any other volatile or non-volatile,non-transitory computer-readable and/or computer-executable memorydevices that store information.

In some embodiments, network interface 1540 is communicatively coupledto processor 1520 and may refer to any suitable device operable toreceive input for the network node, send output from the network node,perform suitable processing of the input or output or both, communicateto other devices, or any combination of the preceding. Network interface1540 may include appropriate hardware (e.g., port, modem, networkinterface card, etc.) and software, including protocol conversion anddata processing capabilities, to communicate through a network.

Other embodiments of the network node may include additional componentsbeyond those shown in FIG. 12 that may be responsible for providingcertain aspects of the network node's functionality, including any ofthe functionality described above and/or any additional functionality(including any functionality necessary to support the solution describedabove).

FIG. 13 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments. Wireless device 110 may include oneor more modules. For example, wireless device 110 may include adetermining module 1610, a communication module 1620, a receiving module1630, an input module 1640, a display module 1650, and any othersuitable modules. In some embodiments, one or more of determining module1610, communication module 1620, receiving module 1630, input module1640, display module 1650 or any other suitable module may beimplemented using one or more processors, such as processor 1320described above in relation to FIG. 10. In certain embodiments, thefunctions of two or more of the various modules may be combined into asingle module. Wireless device 110 may perform the RAR functionalitydescribed above with respect to FIGS. 1-9.

Determining module 1610 may perform the processing functions of wirelessdevice 110. For example, determining module 1610 may configure a message3 in response to a RAR message from a base station indicating modulationformat. Determining module 1610 may include or be included in one ormore processors, such as processor 1320 described above in relation toFIG. 10. Determining module 1610 may include analog and/or digitalcircuitry configured to perform any of the functions of determiningmodule 1610 and/or processor 1320 described above. The functions ofdetermining module 1610 described above may, in certain embodiments, beperformed in one or more distinct modules.

Communication module 1620 may perform the transmission functions ofwireless device 110. For example, communication module 1620 send amessage 3 in accordance with a RAR message from a base station.Communication module 1620 may include a transmitter and/or atransceiver, such as transceiver 1310 described above in relation toFIG. 10. Communication module 1620 may include circuitry configured towirelessly transmit messages and/or signals. In particular embodiments,communication module 1620 may receive messages and/or signals fortransmission from determining module 1610. In certain embodiments, thefunctions of communication module 1620 described above may be performedin one or more distinct modules.

Receiving module 1630 may perform the receiving functions of wirelessdevice 110. As one example, receiving module 1630 may receive from thebase station a RAR message to transmit message 3 with OFDM or DFTS-OFDM.Receiving module 1630 may include a receiver and/or a transceiver, suchas transceiver 1310 described above in relation to FIG. 10. Receivingmodule 1630 may include circuitry configured to wirelessly receivemessages and/or signals. In particular embodiments, receiving module1630 may communicate received messages and/or signals to determiningmodule 1610. The functions of receiving module 1630 described above may,in certain embodiments, be performed in one or more distinct modules.

Input module 1640 may receive user input intended for wireless device110. For example, the input module may receive key presses, buttonpresses, touches, swipes, audio signals, video signals, and/or any otherappropriate signals. The input module may include one or more keys,buttons, levers, switches, touchscreens, microphones, and/or cameras.The input module may communicate received signals to determining module1610.

Display module 1650 may present signals on a display of wireless device110. Display module 1650 may include the display and/or any appropriatecircuitry and hardware configured to present signals on the display.Display module 1650 may receive signals to present on the display fromdetermining module 1610.

Determining module 1610, communication module 1620, receiving module1630, input module 1640, and display module 1650 may include anysuitable configuration of hardware and/or software. Wireless device 110may include additional modules beyond those shown in FIG. 13 that may beresponsible for providing any suitable functionality, including any ofthe functionality described above and/or any additional functionality(including any functionality necessary to support the various solutionsdescribed herein).

FIG. 14 is a block schematic of an exemplary network node 115, inaccordance with certain embodiments. Network node 115 may include one ormore modules. For example, network node 115 may include determiningmodule 1710, communication module 1720, receiving module 1730, and anyother suitable modules. In some embodiments, one or more of determiningmodule 1710, communication module 1720, receiving module 1730, or anyother suitable module may be implemented using one or more processors,such as processor 1420 described above in relation to FIG. 11. Incertain embodiments, the functions of two or more of the various modulesmay be combined into a single module. Network node 115 may perform theRAR functionality described above with respect to FIGS. 1-9.

Determining module 1710 may perform the processing functions of networknode 115. For example, determining module 1710 may formulate the RARmessages described above. Determining module 1710 may include or beincluded in one or more processors, such as processor 1420 describedabove in relation to FIG. 11. Determining module 1710 may include analogand/or digital circuitry configured to perform any of the functions ofdetermining module 1710 and/or processor 1420 described above. Thefunctions of determining module 1710 may, in certain embodiments, beperformed in one or more distinct modules.

Communication module 1720 may perform the transmission functions ofnetwork node 115. As one example, communication module 1720 may send theRAR messages described above to a UE. Communication module 1720 maytransmit messages to one or more of wireless devices 110. Communicationmodule 1720 may include a transmitter and/or a transceiver, such astransceiver 1410 described above in relation to FIG. 11. Communicationmodule 1720 may include circuitry configured to wirelessly transmitmessages and/or signals. In particular embodiments, communication module1720 may receive messages and/or signals for transmission fromdetermining module 1710 or any other module. The functions ofcommunication module 1720 may, in certain embodiments, be performed inone or more distinct modules.

Receiving module 1730 may perform the receiving functions of networknode 115. Receiving module 1730 may receive any suitable informationfrom a wireless device, such as a RAR message 3. Receiving module 1730may include a receiver and/or a transceiver, such as transceiver 1410described above in relation to FIG. 11. Receiving module 1730 mayinclude circuitry configured to wirelessly receive messages and/orsignals. In particular embodiments, receiving module 1730 maycommunicate received messages and/or signals to determining module 1710or any other suitable module. The functions of receiving module 1730may, in certain embodiments, be performed in one or more distinctmodules.

Determining module 1710, communication module 1720, and receiving module1730 may include any suitable configuration of hardware and/or software.Network node 115 may include additional modules beyond those shown inFIG. 14 that may be responsible for providing any suitablefunctionality, including any of the functionality described above and/orany additional functionality (including any functionality necessary tosupport the various solutions described herein).

FIG. 15 shows an example method 2000 in a base station, wherein themethod begins at 2010 with a method in a base station for managingrandom-access procedures with a plurality of wireless devices. At step2020 the method includes transmitting an indication of a modulationformat to configure the modulation format for a random access message 3transmission. As disclosed above, such a transmission may be within aRAR message to a wireless device or UE. In other examples, disclosedabove, such a transmission is within a broadcast channel and received bya plurality of wireless devices. The method optionally includes the step2030 of receiving a transmission from a wireless device according to theindicated modulation format. The method terminates at step 2040.

FIG. 16 shows an example method 2100 in a wireless device or UE, themethod begins at step 2110 for performing a random-access procedure witha network node, and proceeds at step 2120 with the wireless devicereceiving, from a network node, an indication of a modulation format fora random access message 3 transmission to the network node. As disclosedabove, the wireless device may receive the indication within a RARmessage. In other examples, disclosed above, the wireless devicereceives the indication within a broadcast channel and received by aplurality of wireless devices. At step 2130 the method continues withthe wireless device transmitting the random access message 3 accordingto the indicated modulation format. The method ends at step 2140.Modifications, additions, or omissions may be made to the systems andapparatuses described herein without departing from the scope of thedisclosure. The components of the systems and apparatuses may beintegrated or separated. Moreover, the operations of the systems andapparatuses may be performed by more, fewer, or other components.Additionally, operations of the systems and apparatuses may be performedusing any suitable logic comprising software, hardware, and/or otherlogic. As used in this document, “each” refers to each member of a setor each member of a subset of a set.

Modifications, additions, or omissions may be made to the methodsdescribed herein without departing from the scope of the disclosure. Themethods may include more, fewer, or other steps. Additionally, steps maybe performed in any suitable order.

Although this disclosure has been described in terms of certainembodiments, alterations and permutations of the embodiments will beapparent to those skilled in the art. Accordingly, the above descriptionof the embodiments does not constrain this disclosure. Other changes,substitutions, and alterations are possible without departing from thespirit and scope of this disclosure, as defined by the following claims.

Abbreviations used in the preceding description include:

-   -   3GPP 3rd Generation Partnership Project    -   AP Access Point    -   AMM Active Mode Mobility    -   BS Base Station    -   BSC Base Station Controller    -   BTS Base Transceiver Station    -   CDM Code Division Multiplexing    -   CIO Cell Individual Offset    -   CPE Customer Premises Equipment    -   CRS Cell Specific Reference Signal    -   CSI Channel State Information    -   CSI-RS Channel State Information Reference Signal    -   D2D Device-to-device    -   DAS Distributed Antenna System    -   DCI Downlink Control Information    -   DFT Discrete Fourier Transform    -   DL Downlink    -   DMRS Demodulation Reference Signal    -   eNB evolved Node B    -   FDD Frequency Division Duplex    -   HO Handover    -   LAN Local Area Network    -   LEE Laptop Embedded Equipment    -   LME Laptop Mounted Equipment    -   LOS Line of Sight    -   LTE Long Term Evolution    -   M2M Machine-to-Machine    -   MAN Metropolitan Area Network    -   MCE Multi-cell/multicast Coordination Entity    -   MCS Modulation level and coding scheme    -   MRS Mobility Reference Signal    -   MSR Multi-standard Radio    -   NAS Non-Access Stratum    -   NR New Radio    -   OFDM Orthogonal Frequency Division Multiplexing    -   PDCCH Physical Downlink Control Channel    -   PDSCH Physical Downlink Shared Channel    -   PRACH Physical Random-Access Channel    -   PSTN Public Switched Telephone Network    -   PUSCH Physical Uplink Shared Channel    -   PUCCH Physical Uplink Control Channel    -   RB Resource Block    -   RBS Radio Base Station    -   RI Rank Indicator    -   RNC Radio Network Controller    -   RRC Radio Resource Control    -   RRH Remote Radio Head    -   RRU Remote Radio Unit    -   TDD Time Division Duplex    -   TFRE Time Frequency Resource Element    -   TM Transmission Mode    -   TR Transmission Resource    -   TTI Transmission-Time Interval    -   TTT Time to Trigger    -   UCI Uplink Control Information    -   UE User Equipment    -   UL Uplink    -   WAN Wide Area Network

1.-47. (canceled)
 48. A method performed by a base station, wherein thebase station supports Discrete Fourier Transform Spread-OrthogonalFrequency Division Multiplexing, DFTS-OFDM and OFDM modulation formatsfor receiving transmissions, the method comprising: selecting DFTS-OFDMfor an uplink transmission: transmitting a system information messagecomprising an indication of a modulation format to one or more of theplurality of wireless devices to use the selected modulation format fora random access message 3 transmission from the one or more wirelessdevices; receiving a transmission from the wireless device according tothe indicated modulation format and wherein the indicated modulationformat applies to future data transmissions from the wireless device.49. The method of claim 48, wherein the selection of the modulationformat is based on one or more of: a capability of the network node; alink budget for the wireless device; an overhead of transmissions to betransmitted by the wireless device; a determined power level and/orsignal to noise ratio, SNR, of the wireless device; and a random accesspreamble detection criterion.
 50. The method of claim 48, wherein thereceived transmission is in response to an uplink scheduling grantincluded in the random access response message.
 51. A method performedby a user equipment, UE, for configuring one of Discrete FourierTransform Spread-Orthogonal Frequency Division Multiplexing, DFTS-OFDMand OFDM modulation formats for uplink transmissions, the methodcomprising: receiving, in a system information message from a basestation, an indication to configure DFTS-OFDM modulation format for arandom access message 3 transmission to the network node, when thenetwork node selects DTFS-OFDM; and, performing an uplink transmissionto the network node according to the indicated modulation format,wherein the indicated modulation format applies to future datatransmissions from the wireless device.
 52. The method of claim 51,wherein the uplink transmission is a random access message
 3. 53. Themethod of claim 51, wherein the received transmission is in response toan uplink scheduling grant included in the random access responsemessage.
 54. A radio base station supporting Discrete Fourier TransformSpread-Orthogonal Frequency Division Multiplexing, DFTS-OFDM and OFDMmodulation formats for receiving transmissions, the base stationconfigured to: select DFTS-OFDM for an uplink transmission: transmit asystem information message comprising an indication of a modulationformat to one or more of the plurality of wireless devices to use theselected modulation format for a random access message 3 transmissionfrom the one or more wireless devices; receive a transmission from thewireless device according to the indicated modulation format and whereinthe indicated modulation format applies to future data transmissionsfrom the wireless device.
 55. The radio base station of claim 54,wherein the selection of the modulation format is based on one or moreof: a capability of the network node; a link budget for the wirelessdevice; an overhead of transmissions to be transmitted by the wirelessdevice; a determined power level and/or signal to noise ratio, SNR, ofthe wireless device; and a random access preamble detection criterion.56. The radio base station of claim 54, wherein the receivedtransmission is in response to an uplink scheduling grant included inthe random access response message.
 57. A user equipment, UE, configuredto: receive, in a system information message from a base station, anindication to configure DFTS-OFDM modulation format for a random accessmessage 3 transmission to the network node, when the network nodeselects DTFS-OFDM; and, perform an uplink transmission to the networknode according to the indicated modulation format, wherein the indicatedmodulation format applies to future data transmissions from the wirelessdevice.
 58. The UE of claim 57, wherein the uplink transmission is arandom access message
 3. 59. The UE of claim 57, wherein the receivedtransmission is in response to an uplink scheduling grant included inthe random access response message.
 60. A computer program containinginstructions which when executed on a computer perform the method ofclaim
 48. 61. A computer program product or carrier comprising thecomputer program according to claim 60.